Preparation of copper–silicon dioxide nanoparticles with chemical vapor synthesis

Atmospheric pressure chemical vapor synthesis was used to produce copper nanoparticle composites in an amorphous silicon dioxide, i.e., either copper nanoparticles coated with amorphous silicon dioxide or copper nanoparticles embedded in amorphous silicon dioxide matrix. Synthesized metal–organic copper(I) complex was used as a precursor that provided well-defined ratio (1:2) of copper and silicon. The thermal decomposition of the Cu(I) complex molecule leads to homogenous nucleation and formation of copper nanoparticles which are subsequently coated with Si/SiO₂ in the gas phase. The decomposition was greatly enhanced when reductive atmosphere, i.e., H₂/N₂ 10 v% were used instead of pure nitrogen. A narrow size distribution with the geometric mean diameter of the particle agglomerates around 30 nm was observed while the primary size of the copper core particles was around 5 nm.     

13C NMR, 1H NMR and IR spectra of a series of monochloroesters of aliphatic short chain carboxylic acids

¹³C chemical shifts for 14 isomeric monochloroesters of aliphatic carboxylic acids from propanoic acid to hexanoic acid have been determined. Comparisons are made with the literature values for methyl monochloro-octanoate isomers. Substituent effects for all positions are given. Characteristic IR absorption bands are presented and comparisons are made with regard to the isomeric structure. Connections are suggested between observed trends in IR absorption frequencies and some “abnormal” chlorine substituent effects on ¹³C chemical shifts. ¹H NMR spectra of these compounds are considered.     

The total synthesis of (+)-tedanolide

The first total synthesis of the (+)-tedanolide is described. Pivotal steps are the Felkin-selective aldol coupling between C12 and C13 and an efficient Mitsunobu macrolactonization. Selective protecting group transformations and subsequent oxidations generate the macrocyclic triketone. In the endgame of the synthesis, four TBS groups are removed in one reaction and a chemo- and stereoselective final step epoxidation generates (+)-tedanolide.     

FTIR-ATR characterization of langmuir-blodgett assemblies of 1-palmitoyl-2-pyrenedecanoylphosphatidylcholine and dipalmitoylphosphatidylcholine

Langmuir-Blodgett assemblies of 1-palmitoyl-2-pyrenedecanoylphosphatidylcholine and dipalmitoylphosphatidylcholine were transferred from an air/water interface onto germanium or silicon attenuated total reflection (ATR) crystals and were investigated by Fourier transform infrared spectroscopy. A detailed attention has been paid to optimize the deposition conditions and to study the organization of transferred mono- and multimolecular layers.